Building the Quantum Future: LIGENTEC SiN QPIC1550 Photonics

The race to make quantum technologies practical is accelerating. At its core lies a transformative innovation: Quantum Photonic Integrated Circuits (QPICs) operating at 1550 nm—the telecom wavelength that integrates seamlessly with existing fiber infrastructure. The QPIC1550 project, funded by the European Commission’s Horizon Europe programme, represents the first global initiative to pioneer QPICs at this critical wavelength.

It will deliver a universal PIC platform for quantum technologies that will co-integrating III-V key components like on-demand source of highly indistinguishable photons and cutting edge single photon detectors.

As a leader in ultra-low-loss Silicon Nitride (SiN) photonics, LIGENTEC provides the photonic platform upon which the future of quantum communication, sensing, and computing will be built.

Fig. 03: Schematic of the proposed QPIC1550 platform. A QD-based single-photon source (SPS) is coupled to a SiN ultra-low-loss waveguide (ULLW). Mach–Zehnder interferometers are formed using splitters, combiners, and InP-based phase modulators, which act as modulators or switches. SPADs are integrated in InP and waveguide-coupled to the SiN layer. C-band pump lasers are incorporated via InP lasers and SiN passives, while SiN tapered mode expanders enable low-loss fiber coupling.

Building the Platform That Matters

As Work Package Leader for both SiN platform development and demonstrator circuits, LIGENTEC France defines, fabricates, and validates the core integration platform enabling the entire project. Our contributions span from 200mm process development with X-Fab France to delivering ultra-low-loss circuits achieving 0.05 dB/cm propagation losses—essential for quantum applications where every photon counts.

Our AN800 thick-film SiN process delivers the performance quantum demands: wide transparency (400–4000 nm), ultra-low losses, high power handling (>5 W per waveguide), and manufacturing scalability through CMOS-compatible processes. We ensure wafer-level bonding compatibility with active Indium Phosphide components, including single-photon emitters and detectors developed by consortium partners.

This isn’t just about specifications—it’s about providing the reliable foundation that takes quantum devices from research labs to deployable technology.

Enabling Real Quantum Photonics Applications

QPIC1550 will demonstrate three critical use cases powered by LIGENTEC’s photonic circuits:

Quantum Key Distribution: Integrated sources and detectors on a single chip enable compact, stable QKD systems for practical quantum-secured communication beyond specialized installations.

Remote Quantum Computing: Networking distributed processing nodes over standard telecom fibers addresses quantum computing’s biggest scaling challenge.

Quantum Clock Synchronization: Achieving femtosecond-level timing precision across multiple sites opens applications in navigation, fundamental science, and distributed sensing that classical methods can’t match.

From Lab to Industry

Our QPIC1550 roadmap delivers first-generation wafers for integration validation, prototype circuits for application testing, and second-generation demonstrators for fully integrated quantum systems. Each milestone represents progress toward a platform that research groups and industry can actually deploy—not just admire in publications.

This transition to industrial reality has been officially recognized by the European Commission. The EU Innovation Radar recently assessed our bonding-ready 200mm SiN wafers as ‘Market Ready’ with ‘Noteworthy Market Creation Potential.’ This distinction confirms that our technology is not just a research concept, but a mature solution ready to support the scale-up of quantum infrastructure today.

Quantum technologies promise breakthroughs across telecommunications, finance, healthcare, and defense. At LIGENTEC, we’re delivering what makes those promises real: photonic platforms that work reliably, integrate with existing infrastructure, and scale to production volumes.

Explore Further

Want to understand how our Silicon Nitride platform enables quantum innovation? Visit our technology page to explore our capabilities.

Interested in the broader QPIC1550 initiative? Learn more at the QPIC1550 project site.

We’re not just advancing photonics—we’re building the infrastructure for the quantum future.